How does Bobo the Bear work?

Hey.
I'm not necessarily a performer, but I've always wondered how Bobo the Bear works?
It just that he always struck me as a full-body Muppet; mostly because he looks to heavy to operate as a normal Muppet. Is this true - or is he just a normal Muppet that uses a (potentially?) smaller mechanism for his mouth?
If anyone knows, please let me know - I'm just so curious lol! XD
Thanks.